For camera bodies, there was no international warranty all along (for both Nikon and Canon). As for the policy change, we are talking about Canon lenses and flashes. Before Oct 2010, you can get the HK local set (lenses and flashes) which will include international warranty but after that date, the new stock will only include HK/China warranty from HK local sets.
As for whether to go for Tin Cheung or DDElectronics, it is entirely your call.
There is always a risk certain shop might go out of business and your shop warranty will go with it. For HK local warranty, at least you know Canon HK is not as easy to go out of business and you have an option to send it back for repair if you really have no other choice.